Suffice it to say that anyone who has seriously studied the equations of quantum mechanics will assent to Heisenberg's measured (pardon the pun) summary of his celebrated uncertainty principle: We can no longer speak of the behaviour of the particle independently of the process of observation. As a final consequence, the natural laws formulated mathematically in quantum theory no longer deal with the elementary particles themselves but with our knowledge of them.
Personal and Historical Perspectives of Hans Bethe. Quantum Physics. Quantum Physics What it is?

Quantum physics is a branch of science that deals with discrete, indivisible units of energy called quanta as described by the Quantum Theories. Quantum physics invloves the study of the realm of the very small, at the atomic and subatomic level, such as electrons, photons and quarks. Therefore, it’s operating at the below-cell level of the body.

Quantum Physics is also the study of the forces that act on atomic and subatomic entities.
Bells theorem. Epr paradox. Entanglement theory. Quantum weirdness. Unified field theory. Time reversal symmetry. Spacetime and Geometry: Bibliography of Books on General Relativity.